“(2) P is liable to a penalty of 5% of the unpaid tax. (3) If any amount of the tax is unpaid after the end of the period of 5 months beginning with the penalty date, P is liable to a penalty of 5% of that amount. (4) If any amount of the tax is unpaid after the end of the period of 11 months beginning with the penalty date, P is liable to a penalty of 5% of that amount.”
“(1) Liability to a penalty under any paragraph of this Schedule does not arise in relation to a failure to make a payment if P satisfies HMRC or (on appeal) the First-tier Tribunal or Upper Tribunal that there is a reasonable excuse for the failure. (2) For the purposes of sub-paragraph (1)— ( a ) an insufficiency of funds is not a reasonable excuse unless attributable to events outside P's control, ( b ) where P relies on any other person to do anything, that is not a reasonable excuse unless P took reasonable care to avoid the failure, and ( c ) where P had a reasonable excuse for the failure but the excuse has ceased, P is to be treated as having continued to have the excuse if the failure is remedied without unreasonable delay after the excuse ceased.”
“A reasonable excuse may involve an exceptional event but need not necessarily do so.”
"Scott LJ …is of the opinion that the underlying cause of the insufficiency of funds must be an 'unforeseeable or inescapable event'. I have come to the conclusion that this is too narrow in that (a) it gives insufficient weight to the concept of reasonableness and (b) it treats foreseeability as relevant in its own right, whereas I think that 'foreseeability' or as I would say 'reasonable foreseeability' is only relevant in the context of whether the cash flow problem was 'inescapable' or, as I would say, 'reasonably avoidable'. It is more difficult to escape from the unforeseeable than from the foreseeable."
" My references in Salevon to 'the wrongful act of another' and to the distinction between 'the trader who lacks the money to pay his tax by reason of culpable default and the trader who lacks the money by reason of unforeseeable and inescapable misfortune' were directed to the facts of that case. They cannot be regarded as an all-purpose test of what constitutes a reasonable excuse."
“… [I]f the exercise of reasonable foresight and of due diligence and a proper regard for the fact that the tax would become due on a particular date would not have avoided the insufficiency of funds which led to the default, then the taxpayer may well have a reasonable excuse for non-payment, but that excuse will be exhausted by the date on which such foresight, diligence and regard would have overcome the insufficiency of funds.”